Power steering pulley Big or small

[RJChallenger]

I have a saginaw, keyed shaft power steering pump. whats the difference between big block/ small block pulleys. Is it off set ? Diameter? Are all big block challenger pulleys the three spoke style?

[RJChallenger]

HELP please ? Does any one know if you can stick big block brackets on a Saginaw small block pump/pulley for a 70 440. I know the pumps are the same, but will the small block pulley line up or must I get a big block pulley?

[Skid Row]

 I reused my Saginaw pump (Changed from a 340 to 440) bought the brackets from Bouchillan Performance Engineering. Purchased a pulley(3 spoke) on E-bay, But they sell it  also. Yes the off set is different.

[RJChallenger]

Thankyou . Now I wont waste my time on the old pulley. and add it to Santa's list.